This invention relates to a replica plate comprising a transparent plastic substrate and a photo-cured resin, a process for producing the replica plate, and a projection type television including a projection type screen using the replica plate.
In the manufacture of projection type screens for television, general Fresnel lenses, general lenses, optical disk substrates, diffraction gratings or the like, it has been a common practice to make a multiplicity of replica plates by repeating transfer from a matrix having a surface provided with recessed and projected portions or with a certain curved surface.
For the production of the replica plate, there has hitherto been known a method as shown in FIG. 2. In this method, a replica-forming photo-curable resin 3 is placed between a transparent plastic plate 1 and a matrix 2 formed of an organic or inorganic material, the resin 3 is cured by irradiation with energy rays 4, to form photo-cured resin 3', and the matrix 2 is released to obtain a replica plate 5.
According to the conventional method shown in FIG. 2, which is disclosed in Japanese Patent Laid-open No. 177215/86, however, it is difficult to maintain a high level of adhesion between the transparent plastic plate 1 and the photo-cured resin 3'. Thus, there have been the cases of delamination occurring between the transparent plastic plate 1 and the photo-cured resin 3' upon the release of the replica plate 5 from the matrix 2, leaving the photo-cured resin 3' on the matrix 2. Even if the replica plate 5 is released favorably, delamination might occur between the transparent plastic plate 1 and the photo-cured resin 3' during long-time use of the replica plate.